JP2003222553A - Sound detecting method and device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for detecting sound emitted from a specific sound emitting surface of a measuring object while the measuring object is under a normal use condition or operating condition. <P>SOLUTION: This sound detecting device is used for detecting sound emitted from the specific sound emitting surface 8 of a vibrating object 7. This device is equipped with a vibrational accelerometer 15 for detecting vibrational acceleration of the specific surface 8, a vibrational acceleration-vibrational velocity converter 13 for converting vibrational acceleration into vibrational velocity, a microphone 3 for detecting sound pressure near the specific surface 8, and a cross spectrum computation part 6 for computing a cross spectrum of the vibrational velocity and the sound pressure. This device detects only sound emitted from the specific surface 8. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound detecting method for detecting only sound emitted from a specific acoustic radiation surface of a vibrating object and an apparatus using the same.

[0002]

2. Description of the Related Art In recent years, in order to control noise emitted from home electric appliances which require quietness, sound emitted from individual parts which can be a sound source is detected and a sound source is identified or an abnormal sound is emitted. It is important to sort out defective parts. Conventionally, sound intensity measurement by the two-microphone method has been used to detect sound emitted from a specific sound emitting surface of a vibrating object. This is a method of approximating the air particle velocity vector and the sound pressure from the sound pressure measured by two microphones that are separated by a certain distance, and calculating the vector quantity representing the acoustic energy passing through the space from the product. There is a method of detecting a sound emitted from a specific acoustic emission surface of a vibrating object by specifying the emission surface emitting the sound according to the magnitude and direction of the vector.

[0003]

However, when the sound emitted from a specific acoustic emission surface of a vibrating object is detected by the sound intensity measurement by the two-microphone method, there are the following problems. (1) Since all the acoustic energy passing through the space is measured, it is not possible to remove the acoustic energy of sound emitted from a radiation surface other than the specific radiation surface of interest.
Therefore, if the acoustic energy of the sound emitted from the specific emission surface is equal to or smaller than the acoustic energy of the sound emitted from the other emission surfaces, the emission sound from the specific emission surface cannot be detected. (2) Since all the acoustic energy passing through the space is measured, the acoustic energy of the radiated sound from an object other than the target object cannot be removed. Therefore, if the acoustic energy of the sound emitted from the object to be measured is equal to or smaller than the acoustic energy of the sound emitted from other objects, the sound emitted from the object to be measured cannot be detected. (3) Since all the acoustic energy passing through the space is measured, it is impossible to remove the acoustic energy of the reflected sound that the radiation sound from the target specific radiation surface is reflected by another object and propagates. Therefore, the acoustic energy of the radiated sound cannot be accurately calculated, and an error occurs in the identification of the radiation surface, so that the sound radiated from the specific acoustic radiation surface of the vibrating object cannot be detected. (4) It is necessary to calculate out-of-plane acoustic intensities of the measurement plane or out-of-plane and three-directional acoustic intensities of two in-plane directions at a large number of points on the two-dimensional measurement plane that are distant from the radiation surface. It takes a lot of work and time to obtain the measurement result.

In order to solve these problems, only the object to be measured is installed in an anechoic room having high soundproof performance,
Sound intensity needs to be measured. In addition, a microphone moving device or a large number of microphones and analyzers are required to obtain a result in a short time measurement. Therefore, it is not possible to measure the measurement object in a normal use state or operating state, and when a plurality of devices are used or operated in combination, measurement of some of the devices cannot be performed. It is impossible. For example, it is not suitable as a product inspection method incorporated into a manufacturing line or the like.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to measure an object to be measured in a normal use state or operating state. A method for detecting sound radiated from a specific acoustic radiation surface and an apparatus using the method are provided.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is a sound detecting method for detecting a sound radiated from a specific acoustic radiation surface of a vibrating object. Simultaneously detecting the vibration velocity of the acoustic radiation surface and the sound pressure in the vicinity of the specific acoustic radiation surface, then calculating the cross spectrum of the vibration velocity and the sound pressure, the radiation sound from the specific acoustic radiation surface other than The reflected sound that is reflected by the object and propagates,
The sound emitted from the sound emitting surface other than the specific sound emitting surface and the object other than the vibrating object is removed so that only the sound emitted from the specific sound emitting surface is detected.

According to a second aspect of the present invention, there is provided a sound detecting device for detecting a sound radiated from a specific acoustic radiation surface of a vibrating object, the vibration detecting means detecting a vibration velocity of the specific acoustic radiation surface. A sound pressure detecting means for detecting a sound pressure in the vicinity of the specific sound emitting surface, and a calculating means for calculating a cross spectrum of the vibration velocity and the sound pressure, and a sound emitted from the specific sound emitting surface. Only detected.

According to a third aspect of the present invention, in the sound detecting device according to the second aspect, the vibration detecting means includes a vibration sensor for detecting a vibration displacement or a vibration speed in a non-contact manner, and the sound pressure detecting means is a microphone. The vibration sensor and the microphone are integrated.

According to a fourth aspect of the present invention, in the sound detecting device according to the second aspect, the vibration detecting means includes a vibration sensor that is adhered or screwed to the vibrating object to detect a vibration acceleration, and the sound pressure is detected. The detection means includes a microphone,
The vibration sensor and the microphone are integrated by elastically supporting the microphone via an elastic member on the vibration sensor.

According to a fifth aspect of the present invention, in the sound detecting device according to the second aspect, the vibration detecting means includes a vibration sensor that presses against the vibrating object to detect vibration acceleration.
The sound pressure detecting means includes a microphone, and the vibration sensor and the microphone are integrated by elastically supporting the microphone via an elastic member on the vibration sensor.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a configuration diagram of a sound detecting device according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of a sound detecting device according to a second embodiment of the present invention, and FIG. Block diagram of a third embodiment of a sound detection device according to
FIG. 4 is a graph showing a vibration isolation effect in a microphone elastically supported by a leaf spring, FIG. 5 is a configuration diagram of a sound detecting device according to a fourth embodiment of the present invention, and FIG. 6 is elastically supported by a rubber member. FIG. 7 is a configuration diagram of an application example of the sound detecting device according to the present invention, which is a graph showing the vibration isolation effect of the microphone.

In the first embodiment of the sound detecting device according to the present invention, as shown in FIG. 1, a vibration displacement meter 1, a vibration displacement-vibration velocity converter 2, a microphone 3, an A / D converter 4, 5
And a cross spectrum calculation unit 6. The vibration displacement meter 1 is installed in the vicinity of the acoustic radiation surface 8 of the vibrating object 7 in a non-contact state, and the microphone 3 is located in the vicinity of the acoustic radiation surface 8 of the vibration displacement meter 1 and the vibrating object 7 and 8 is installed in a non-contact state.

The vibration displacement meter 1 and the microphone 3 are integrated into one sensor probe 10. By using the vibration displacement meter 1 and the microphone 3 as one sensor probe 10, it becomes easy to efficiently move the sensor probe 10 to the vibrating object 7, which is the measurement object, and install it at a desired position. Measurement at the measurement point can be performed in a short time. The vibration displacement meter 1 and the microphone 3 may be separate bodies.

The vibration displacement meter 1 is a specific one of the acoustic radiation surface 8.
The vibration displacement at the point is detected in a non-contact manner and an analog electric signal proportional to the vibration displacement is output. The vibration displacement-vibration velocity converter 2 converts the analog electric signal output from the vibration displacement meter 1 in proportion to the vibration displacement into an analog electric signal proportional to the vibration velocity and outputs the analog electric signal.

The microphone 3 detects the sound pressure in the vicinity of a specific point on the acoustic radiation surface 8 on which the vibration displacement meter 1 measures the vibration, and performs sound pressure-electric conversion to output an analog electric signal proportional to the sound pressure. The A / D converters 4 and 5 digitize the analog electric signals output from the vibration displacement-vibration velocity converter 2 and the microphone 3 into voltage values at certain fixed time intervals.

The cross spectrum calculation unit 6 has a voltage value proportional to the vibration speed digitized by the A / D converter 4 and a voltage value proportional to the sound pressure digitized by the A / D converter 5. A calculation process for calculating the cross spectrum is performed.

The operation of the first embodiment of the sound detecting apparatus according to the present invention configured as above will be described. First, the sensor probe 10 in which the vibration displacement meter 1 and the microphone 3 are integrated is installed so as to face the acoustic emission surface 8 of the vibrating object 7, which is the measurement target. At this time, the sensor probe 10 and the sound emitting surface 8 are in a non-contact state.

Next, the vibration displacement meter 1 is connected to the acoustic radiation surface 8-1.
It detects the vibration displacement of the point and outputs an analog electric signal.
Then, the vibration displacement-vibration velocity converter 2 converts the analog electric signal proportional to the vibration displacement output from the vibration displacement meter 1 into an analog electric signal proportional to the vibration velocity. Furthermore, the A / D converter 4 digitizes an analog electric signal proportional to the vibration speed output from the vibration displacement-vibration speed converter 2 into a voltage value at a certain fixed time interval.

At the same time, the microphone 3 detects the sound pressure in the vicinity of the vibration displacement measurement point on the acoustic radiation surface 8 and outputs an analog electric signal. Then, the A / D converter 5 digitizes the analog electric signal proportional to the sound pressure output from the microphone 3 into a voltage value at a certain fixed time interval.

Next, 1 of the acoustic radiation surface 8 to be measured is
A cross spectrum of the digitized voltage value proportional to the vibration speed of the point and the digitized voltage value proportional to the sound pressure in the vicinity of the acoustic radiation surface 8 is calculated by the cross spectrum calculation unit 8. By the calculation processing by the cross spectrum calculation unit 8, of the spectrum components included in the voltage value proportional to the sound pressure, the spectrum components not included in the voltage value proportional to the vibration speed are removed.

Further, since the sound pressure is measured in the vicinity of the sound radiation surface 8 which is the measurement object, the sound emitted from the sound radiation surface 8 is reflected by another object and propagates, and the sound radiation surface. 8
Since a large time difference occurs between the vibration velocities of, the reflected sound is removed by the cross spectrum calculation processing.

Therefore, the reflected sound in which the radiated sound from the acoustic radiation surface 8 is reflected and propagated to other objects, the radiated sound from the radiation surface other than the acoustic radiation surface 8 and the object other than the vibrating object 7 are removed, Only the sound radiated by vibrating the sound emitting surface 8 can be measured.

Next, the second embodiment of the sound detecting device according to the present invention is, as shown in FIG. 2, a vibration velocimeter 11, a microphone 3, A / D converters 4, 5 and a cross spectrum calculation section. It consists of 6. The vibrating speed meter 11 is installed in the vicinity of the sound emitting surface 8 of the vibrating object 7 in a non-contact state, and the microphone 3 is located near the sound emitting surface 8 of the vibrating speed meter 11 and the vibrating object 7 and in the sound emitting surface. 8 is installed in a non-contact state.

The vibration velocity meter 11 and the microphone 3 are integrated into one sensor probe 20. The vibration velocity meter 11 and the microphone 3 are combined into one sensor probe 2
By setting to 0, it becomes easy to efficiently move the sensor probe 20 to the vibrating object 7 that is the measurement object and install it at a desired position, and it is possible to perform measurement at a plurality of measurement points in a short time. it can. The vibrating speed meter 11 and the microphone 3 can be separated.

The vibration velocimeter 11 detects the vibration velocity at a specific point on the acoustic radiation surface 8 in a non-contact manner and outputs an analog electric signal proportional to the vibration velocity. In addition, the vibration displacement meter 1 and the vibration displacement-vibration velocity converter 2 are used as the vibration sensor instead of the vibration velocity meter 11 which directly detects the vibration velocity, except that the vibration velocity meter 11 is used as in the first embodiment shown in FIG. It is a simple structure. Therefore, the description of the components having the same reference numerals as those shown in FIG. 1 and the operation description of the second embodiment will be omitted.

Next, in the third embodiment of the sound detecting device according to the present invention, as shown in FIG. 3, a vibration accelerometer 12, a vibration acceleration-vibration velocity converter 13, a microphone 3, A /
It is composed of D converters 4 and 5 and a cross spectrum calculation unit 6. The vibration accelerometer 12 is installed in contact with the acoustic radiation surface 8 of the vibrating object 7 by bonding or screwing, and the microphone 3 is installed near the acoustic accelerometer 12 and the acoustic radiation surface 8 of the vibrating object 7. It is installed without direct contact with.

The vibration accelerometer 12 and the microphone 3 are integrated into one sensor probe 30. At that time, the vibration of the acoustic radiation surface 8 propagates to the microphone 3 via the vibration accelerometer 12, which may cause an error in the sound pressure measurement. Therefore, the vibration accelerometer 12 is elastically supported via the leaf spring 14 to be integrated.

A graph of the vibration isolation effect of the microphone 3 elastically supported by the leaf spring 14 (the horizontal axis represents frequency, and the vertical axis represents a screwing type vibration accelerometer 12 to the microphone 3).
Fig. 4 shows the vibration transmissibility to the. From FIG. 4, it is considered that the resonance frequency of the support system of the microphone 3 is around 18 Hz. Also, a resonance phenomenon is seen near 70 Hz.
Since this resonance did not exist without the output cable of the microphone 3, it is considered that this resonance is not the higher order resonance of the support system of the microphone 3 but the resonance caused by the output cable as a spring.

Although such a resonance phenomenon occurs, the measurement frequency range of the microphone 3 is 100 Hz to 10 kHz.
It is defined as z, and a vibration isolation effect of 25 dB or more is recognized at 100 Hz or more. In this frequency range, the leaf spring 14
It can be seen that the microphone 3 is sufficiently isolated.

As described above, the adhesive or screw-type vibration accelerometer 12 and the microphone 3 are integrated into one sensor probe 30, so that the sensor probe 30 can be obtained.
Can be efficiently moved to the vibrating object 7, which is the measurement object, and installed at a desired position, and measurement at a plurality of measurement points can be performed in a short time. Note that the vibration accelerometer 12 and the microphone 3 can be separate bodies.

The vibration accelerometer 12 detects the vibration acceleration at a specific point on the acoustic radiation surface 8 and outputs an analog electric signal proportional to the vibration acceleration. The vibration acceleration-vibration velocity converter 13 converts an analog electric signal proportional to the vibration acceleration output by the vibration accelerometer 12 into an analog electric signal proportional to the vibration velocity and outputs the analog electric signal.

Instead of the vibration displacement meter 1 and the vibration displacement-vibration velocity converter 2 as vibration sensors, a vibration accelerometer 12 for detecting vibration acceleration and a vibration acceleration-vibration velocity converter 13 are used.
The configuration is similar to that of the first embodiment shown in FIG. Therefore, the description of the components having the same reference numerals as those shown in FIG. 1 and the operation description of the third embodiment will be omitted.

Next, in the fourth embodiment of the sound detecting device according to the present invention, as shown in FIG. 5, the vibration accelerometer 15 used while being pressed against the acoustic radiation surface 8 of the vibrating object 7, Vibration acceleration-vibration velocity converter 13, microphone 3, A /
It is composed of D converters 4 and 5 and a cross spectrum calculation unit 6.

The vibration accelerometer 15 and the microphone 3 are integrated into one sensor probe 40. At this time, the vibration of the acoustic radiation surface 8 propagates to the microphone 3 via the vibration accelerometer 15, which may cause an error in sound pressure measurement. Therefore, the vibration accelerometer 15 and the microphone 3 are integrated by adhesion via the rubber member 16, and the microphone 3 is elastically supported by the vibration accelerometer 15.

A graph of the vibration isolation effect in the microphone 3 elastically supported by the rubber member 16 (the horizontal axis represents frequency,
FIG. 6 shows the sound pressure level on the vertical axis. FIG. 6 shows a result of closing the grid of the microphone 3 so that the microphone 3 does not react to the sound pressure but reacts only to the vibration of the acoustic radiation surface 8 propagated via the pressing type vibration accelerometer 15. . When the microphone 3 is brought into contact with the vibration accelerometer 15 of the direct pressing type without using the rubber member 16 (contact in FIG. 6), the acoustic radiation surface 8 does not vibrate (background noise in FIG. 6). It can be seen that there is a reaction of about 60 dB at the maximum, and the microphone 3 may react to the vibration of the acoustic radiation surface 8 to cause an error in sound pressure measurement.

On the other hand, when the microphone 3 is elastically supported by the pressing type vibration accelerometer 15 using the rubber member 16, the measurement result (elastic support in FIG. 6) is 7 kHz or less, which is darker than the contact in FIG. Close to noise. Therefore, at 7 kHz or less, the pressing type vibration accelerometer 1 using the rubber member 16 is used.
Since the microphone 3 is elastically supported by 5, the sound pressure measurement error caused by the vibration of the acoustic radiation surface 8 can be reduced.

The vibration accelerometer 15 detects the vibration acceleration at a specific point on the sound emitting surface 8 while being pressed against the sound emitting surface 8, and outputs an analog electric signal proportional to the vibration acceleration. The vibration acceleration-vibration velocity converter 13 converts the analog electric signal proportional to the vibration acceleration output by the vibration accelerometer 15 into an analog electric signal proportional to the vibration speed and outputs the analog electric signal.

Instead of the vibration displacement meter 1 and the vibration displacement-vibration velocity converter 2 as vibration sensors, a vibration accelerometer 15 for detecting vibration acceleration and a vibration acceleration-vibration velocity converter 13 are used.
The configuration is similar to that of the first embodiment shown in FIG. Therefore, the description of the components having the same reference numerals as those shown in FIG. 1 and the operation description of the fourth embodiment will be omitted.

Next, using the sound detecting device according to the present invention,
An external MO drive 18 connected to a computer main body 17 placed in a commonly used office as shown in FIG.
FIG. 8 shows a graph of the measurement result of the sound radiated by (horizontal axis is frequency, vertical axis is cross spectrum level).

The vibration acceleration accelerometer 15 for pressing the vibration acceleration of the acoustic radiation surface to be measured by the external MO drive 18
The analog electric signal detected by the vibration accelerometer 15 is converted into an analog electric signal proportional to the vibration speed by the vibration acceleration-vibration speed converter 13 and then by the A / D converter 4 at 1/12800 second intervals. Digitally converted to a voltage value.

At the same time, an external M
Sound pressure at a position of 13 mm from the sound emission surface of the O drive 18 is measured, and an analog electric signal proportional to the sound pressure output by the microphone 3 is digitally converted into a voltage value at 1/12800 second intervals by the A / D converter 5. did.

After that, the cross spectrum of the 2048 voltage values proportional to the vibration speed and the 2048 voltage values proportional to the sound pressure are set in the cross spectrum calculation unit 6 for 1 for 20.48 seconds.
The calculation was repeated 28 times, and the average value was calculated. Figure 8
Is displaying the result.

FIG. 9 shows that the analog electric signal output from the microphone 3 and proportional to the sound pressure is digitally converted into voltage values at intervals of 1/12800 seconds by the A / D converter 5, and 2048 output signals are output in proportion to the sound pressure. It is a graph (horizontal axis shows frequency, vertical axis shows sound pressure level) as a result of calculating the average value by repeating 128 times of calculation of the power spectrum of voltage value for 20.48 seconds.

In FIG. 9, the sound of the external MO drive 18 is masked by the background noise such as the sound of the air conditioner. Also, the sound of the computer main body 17 is the external MO drive 1
The sound of MO drive 18 is not detected accurately.

On the other hand, in FIG. 8 showing the measurement result by the sound detecting method according to the present invention and the apparatus using the same, the background noise such as the sound of the air conditioner and the sound of the computer 17 are largely removed,
The sound of the MO drive 18 can be detected.

Further, the sensor probe 10 using the non-contact type vibration displacement meter 1, the sensor probe 20 using the non-contact type vibration velocity meter 11, and the sensor probe 40 using the pressing type vibration accelerometer 15 are used. In this case, the sensor probe 10, 20, 40 is held by an industrial robot and positioned on a specific acoustic radiation surface of the measurement object, so that it can be applied to an online inspection performed in a production line of home appliances or the like. .

[0047]

As described above, according to the invention of claim 1, the measurement object can be measured in a normal use state or an operating state without using an anechoic chamber having high soundproof performance. Only the sound emitted from a particular acoustic emission surface of the object can be detected. Further, it can be applied to a product inspection method that is used by incorporating it into a manufacturing line or the like.

According to the second aspect of the present invention, without using an anechoic chamber having a high soundproof performance, the measurement object is kept in a normal use state or an operating state, and specific acoustic radiation of the measurement object is performed. Only the sound emitted from the surface can be detected. Further, it can be applied to a product inspection device used by being incorporated in a manufacturing line or the like.

According to the third aspect of the present invention, by integrating the vibration sensor and the microphone, it becomes easy to efficiently move them to the object to be measured and install them at a desired position. It is possible to carry out measurement in a short time. Further, since the vibration and the sound pressure can be measured in a non-contact manner, the measurement object will not be affected by the measurement.
Furthermore, since the vibration sensor can measure the vibration in a non-contact state with respect to the measurement target, it is convenient.

According to the fourth aspect of the present invention, by integrating the vibration sensor and the microphone, it becomes easy to efficiently move them to the object to be measured and install them at a desired position. It is possible to carry out measurement in a short time. Further, since the microphone is supported by the vibration sensor via the elastic member, it is possible to reduce the vibration of the acoustic radiation surface propagating to the microphone via the vibration sensor.

According to the fifth aspect of the present invention, by integrating the vibration sensor and the microphone, it becomes easy to efficiently move them to the object to be measured and install them at a desired position. It is possible to carry out measurement in a short time. Further, since the microphone is supported by the vibration sensor via the elastic member, it is possible to reduce the vibration of the acoustic radiation surface propagating to the microphone via the vibration sensor. Furthermore, since the vibration and the sound pressure can be simultaneously measured by simply pressing the vibration sensor against the object to be measured, it is easy to use.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of a sound detection device according to the present invention.

FIG. 2 is a configuration diagram of a second embodiment of a sound detection device according to the present invention.

FIG. 3 is a configuration diagram of a third embodiment of a sound detection device according to the present invention.

FIG. 4 is a graph showing a vibration isolation effect in a microphone elastically supported by a leaf spring.

FIG. 5 is a configuration diagram of a fourth embodiment of a sound detecting device according to the present invention.

FIG. 6 is a graph showing a vibration isolation effect in a microphone elastically supported by a rubber member.

FIG. 7 is a configuration diagram of an application example of a sound detection device according to the invention.

FIG. 8 is a graph showing the measurement result of the sound radiated by the external MO drive connected to the computer main body using the sound detection device according to the present invention.

FIG. 9 is a graph showing measurement results of sound radiated by an external MO drive connected to the computer body.

[Explanation of symbols]

1 ... Vibration displacement meter, 2 ... Vibration displacement-vibration velocity converter, 3 ...
Microphone 4,5, A / D converter, 6 ... Cross spectrum calculator, 7 ... Vibrating object, 8 ... Acoustic emission surface, 10,
20, 30, 40 ... Sensor probe, 11 ... Vibration speed meter,
12 ... Adhesive or screw-type vibration accelerometer, 13 ... Vibration acceleration-vibration velocity converter, 14 ... Leaf spring, 15 ... Push-type vibration accelerometer, 16 ... Rubber member, 17 ... Computer body, 18 ... Outside Attached MO drive.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kohei Yamamoto             3-20-2041 Higashimoto-cho, Kokubunji City, Tokyo             Kobayashi Institute of Science Research (72) Inventor Koji Yoshikawa             3-20-41 Higashimoto-cho, Kokubunji, Tokyo             On Co., Ltd. F-term (reference) 2G064 AB13 BA02 BA12 CC13 CC26                       CC42

Claims (5)

[Claims] 1. A sound detection method for detecting a sound radiated from a specific acoustic radiation surface of a vibrating object, wherein a vibration velocity of the specific acoustic radiation surface and a sound pressure in the vicinity of the specific acoustic radiation surface are detected. Simultaneously detecting, and then calculating the cross spectrum of the vibration velocity and the sound pressure, the reflected sound that the sound emitted from the specific acoustic radiation surface is reflected by another object and propagates, and other than the specific acoustic radiation surface. The sound detecting method, wherein the sound emitted from the sound emitting surface and the object other than the vibrating object are removed to detect only the sound emitted from the specific sound emitting surface. 2. A sound detecting device for detecting a sound radiated from a specific acoustic radiation surface of a vibrating object, the vibration detecting means detecting a vibration velocity of the specific acoustic radiation surface, and the specific sound. A sound pressure detecting means for detecting a sound pressure in the vicinity of the radiation surface and a calculation means for calculating a cross spectrum of the vibration velocity and the sound pressure are provided, and only the sound emitted from the specific acoustic radiation surface is detected. Characteristic sound detection device. 3. The sound detecting device according to claim 2,
The sound detecting device is characterized in that the vibration detecting means includes a vibration sensor that detects a vibration displacement or a vibration speed in a non-contact manner, and the sound pressure detecting means includes a microphone, and the vibration sensor and the microphone are integrated. 4. The sound detecting device according to claim 2,
The vibration detection unit includes a vibration sensor that is bonded or screwed to the vibrating object to detect vibration acceleration, the sound pressure detection unit includes a microphone, and the vibration sensor elastically supports the microphone via an elastic member. A sound detecting device, characterized in that the vibration sensor and the microphone are integrated. 5. The sound detection device according to claim 2,
The vibration detecting unit includes a vibration sensor that presses against the vibrating object to detect a vibration acceleration, the sound pressure detecting unit includes a microphone, and the vibration sensor elastically supports the microphone via an elastic member to vibrate. A sound detection device characterized by integrating a sensor and the microphone.